[Studies on the sensitivity test of anticancer agents with special reference to double layer colony forming assay].

The necessity to assess the effect of chemotherapeutic agents on the patients beforehand treatment has been stressed. In 1977, Salmon & Hamburger developed a new method to evaluate the drug sensitivity using cell suspension derived from the patients. They called the method as "human tumor stem cell assay". Since then, many reports were published about the correlation between the clinical outcomes and the results of human tumor stem cell assay, and high relationship between them was documented. The present study was undertaken to evaluate the method using the modified system; double layer colony forming assay, cell growth curve, tritiated thymidine uptake and flow cytometry. The drugs used in this study were adriamycin (ADR) and cis-platinum (C-DDP). We chose the human small cell lung cancer cell line PC-6 as a target cell. The conclusions are follows. The effects of ADR and C-DDP were concentration dependent respectively. The time dependent effect of C-DDP on PC-6 was revealed by enhancement of lethal effect, when they were exposed to the drug for 24 hours. A possibility exists that reproductive death would take place among PC-6 by ADR, along with DNA injury. It is one of the explanations for reduction of colony formation in contrast to increase in cell number. The effect of C-DDP on PC-6 was diminished with time. This phenomenon was reflected on double layer colony forming assay, and was possible explanation for reduction of colony formation which was greater than that of expected from cell growth curve.(ABSTRACT TRUNCATED AT 250 WORDS)